Sterilised in Canada, the imported moths were dropped by drone over orchards so the local population will invariably breed with the sterilised moths, drastically reducing the resident population.
"On a 100ha orchard – this orchard we are standing in – there was just one adult codling moth captured – male – all season in all of their pheromone traps," Dr Walker said.
As larvae, they are fed a red dye which gives their bodies a pink hue when pressured, for easy identification. 80,000 each week are chilled to 1 C to settle them down for the 36-hour flight over the Pacific Ocean.
Initially the release of codling moths caused harm to humans because the scientists released them by hand from mountain bikes requiring one-handed riding that resulted in too many crashes.
A remote-control fixed-wing plane was also used for the release but now a drone is taking over duties for greater precision.
The moth sterilisation technique has been approved by Biogrow, enabling an organic apple orchard to be incorporated in the Central Hawke's Bay trial.
Plant & Food Research Science Group Leader for Biosecurity, Professor Max Suckling said the technology could be rolled out further, especially if there was an incursion of a new pest.
"Biosecurity is massively important to the economy and something like the brown marmorated stink bug is likely to be worth hundreds of millions, if not billions of dollars, to the New Zealand economy - taking that money away from the people that are producing food," he said.
"It looks like the sterile insect technique might be able to be used against the brown marmorated stink bug as well."
The stink bug has recently been found in three Japanese car shipments and would attack grapes, kiwifruit, apples, citrus, stone-fruit, corn and many other valuable crops.
Made with funding from
